Take an existing cam and copy it onto a piece of paper to be used as a template. You can download an image of a Super Speed cam at SouthBristolViews.com. For this you can use any sturdy material that is .032 inches thick or slightly less. The base of the calibration test cam can be flat on the base if you wish. ( My P33 is 0.55 inches high at the lead edge. The right or high end is 0.70 inches). The infinity point is 0.695 inches. Make the test cam ramp up in the first half of the length of the cam from 0.55 to 0.695 and keep the last half at 0.695.
Alternate: draw a trapezoid with a 1.5 inch base, the sides angled inward 70, the lead (left) side .55 inches high to increase to .695 inches near the middle and remain at .695 inches high to the right edge.
Check your test cam with a caliper. It is critical that the measurement is exact and that the infinity area is parallel to the base of the cam.

Now open your camera bed to 90 degrees and leave the front standard in the body. Now turn the camera upside down and look under the extreme left rangefinder window. The rangefinder calibration adjustments are under the cover that is now visible on the bottom left edge of the rangefinder housing. Remove the cover. Look at the chrome cam follower arm, it should be parallel to the rangefinder housing and the clamp edge just below or at midway between the base of the slot in the moveable mirror shaft and the rangefinder housing. Fabricate a spacer to slide under the cam follower arm to keep it parallel to the rangefinder housing. (Folded paper works). Insert spacer between the rangefinder housing and the cam follower arm. Now run the rails out so that the cam actuator can move its full travel. Insert the test cam into the cam slot in the rangefinder tube. Verify that the cam is under the edge of the cam follower arm and that the cam follower arm is in front of the distance scale actuator arm. Run the rails inward until the cam is on the .0695 inch high section of the cam and lock the rails.

Mount the camera on a tripod and set the rangefinder on an infinity target at least 5000 feet away. Loosen the cam follower arm clamp 1/8 to ¼ of a turn. Turn the moveable mirror shaft as needed to bring the images in the rangefinder viewer window into coincidence. (TIP: if the moveable mirror has come off the shaft and you have reattached it or replaced the moveable mirror then place a small flashlight such as a 1 AAA cell LED over the moveable mirror window and adjust the moveable mirror shaft until the light is reflected onto the fixed mirror. Looking at the fixed mirror from behind as if the view window were in place adjust the moveable mirror until the flashlight LED is centered left to right on the fixed mirror. Complete the calibration once the rangefinder is reinstalled in the camera.) Tighten the cam follower arm clamp screw to hold the setting. Verify that infinity image is still in coincidence. Remove the cam follower arm support spacer. Remove the test cam and reinstall the factory cam. Run the rails fully in then out .040 inch. (1mm=.0394, well within factory tolerance). Check that the cam is under the follower arm and that the arm is in front of the distance scale actuator. Loosen the set screw (s) on the cam actuator bracket at the rear of the rails and move it in or out until the infinity target is in coincidence in the rangefinder view window. Tighten the cam actuator bracket screw(s) and verify that the infinity setting did not move. Reinstall the cam follower arm clamp cover. Test the lens infinity stop setting by moving the front standard to the infinity stops and checking the ground glass image with a loupe. Once the infinity stops are correct, verify the correct operation of the rangefinder by focusing on objects at several different distances and comparing the rangefinder image to the ground glass image.

Thanks Charles. That's a great write-up and will be very useful to people.

I tend to back the rails up to the stop when doing infinity. It creates a permanent set position and works better for the needle at the top.

Speaking of which, if the flash calculator/distance scale needle on top does not show infinity when finishing your setup, it can be easily fixed. The needle is simply pressed onto the shaft with a touch of nailpolish type material holding it on. Mine didn't even need the nailpolish to hold as it was a tight enough fit without it. The top plastic plate is easily removed and the needle can then be repositioned at infinity.

Also, I created an infinity target to do this. It's easier than finding something that far away to focus on. I have it in a PDF file to print out that should work for anyone who would like it. I never did get to put it up on my site for download. Maybe sometime soon...

Measurements were based on two P34 and one P33 cam with an out of calibration rangefinder taken out of the camrea body and serviced once I figured everything out and made the measurements with a digital caliper while the rangefinder was out of the camera.

I wrote it so that it could be placed in the Technical Information section of the Home Page. Being the board is undergoing repairs and or upgrades I decided to post it here for now.

NEXT UP: Measuring cams at given distances to go with the movement factor so that a percise cam can be cut from scratch without trial and error.
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I would be interested in the infinity target and how you made it. I have a piece of mylar left over from the last solar eclipse that I place over the RF windows and the sun made a nice small dot to line up. I placed the mylar over the lens and did the same for checking the infinity stops.
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TO GET the rangefinder tube to function properly: Remove the tube from the camera body. Open the end of the tube with the cam spring. Pour all plungers, balls and spacers into a suitable container. Flush the plungers (2), balls (44), spacers (43), and tube with a no residue leaving degreaser. I find seperating the balls and spacers into seperate sections aids reassembly. Sprinkle EXTRA FINE GRAPHITE ( standard powdered graphite is too coarse and does not work well) on the slide and slide plunger that remailn in the tube. Coat the slide heavily both top and bottom. Coat the balls and spacers generously with the extra fine graphite and reassemble -Ball-Spacer-Ball until all are in the tube then coat the long plunger and insert it flat end first, coat the spring plunger and install the spring and crimp the open end as it was initally. Install a cam in the slot between the spring plunger and long plunger and operate the slide a few times. All sholud move smoothly. Reinstall the tube in the camera and adjust so that slide moves freely in the bed at 90 0. For badly bent slides, place a support under the slide at the bend and pull in the opposite direction until the slide stays straight with no pressure applied. This is easiest done while lthe tube is out of the camera.
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Technical Reference for all of this was:

Super Graphic and Super Speed GRaphic Service Instructions and Parts List , reprint from Craig Camera, and is listed as a 1963 factory manual.
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I printed the test atrget out at my printer's highest settings and it works fine IF the camera is perpindicular to the test target. I recomend setting the camera up on a tripod, measure from the right and left edges of the camera to the target and set the distances to be equal. My test distance was 2 1/2 feet.

You're 100% right. The left/right sides of the target have to be semi close to perfect in being the equal distances from the camera. Sorry, when I designed it and used it this was obvious to me through my train of thought and It never dawned on me to mention it or add it to the instructions. It was originally just made to make the repair of a junker Super simpler. One of those late night ideas of "Hey, why didn't anyone ever...". When I get the time, I'll update the text on the page. Others may not realize the importance of correct positioning.

Just a curiosity note. After finishing this design, I realized that I could go ahead and make marks for all the "standard" focusing distances so it could all be done with the camera and target sitting in a single position. Sounded simple. The math was easy as was the design. _After_ I printed it out, I realized that it only worked at one single exact distance from the camera It would be useful if attached to a focusing jig with a set distance, but how many cameras do we adjust? Ah-well, it was a fun project anyway...

Images 1 thru 6 were composed (taken) with Super Speed #653079 who's date code is B4A. This is the camera I discovered how to calibrate the rangefinder on as when I first went out to shoot it the rangefinder was way off, distance scale showing 17 feet on an object 50 feet away. I cleaned and lubed the 1000 speed shutter with lens serial number 4506341, a 135mm Rodenstok Graflex Optar. Image #6 was rangefinder focused on the walkway between the two towers and was shot at f11 @ 1/1000.

Images 7 thru 12 were shot with Super Speed #647199. I made many mechanical repairs on the body and patched the bellows. I cleaned and lubed the 1000 speed shutter with lens serial number 4288832, a 135mm Rodenstok Graflex Optar. Image 11 was focused on the hat on the bench and shot at f11 @ 1/1000 second. All exposures were between 1/125 @ f32 to 1/1000 @ f11. Focusing was via rangefinder and distance scale referenced to HyperFocal distances caculated with Fcalc.

I used the electronic shutter release in both cameras on all images.

All images are on Ilford HP5 plus, metered with a Gossen Luna Pro F in ambient mode (general reading of the afternoon sun). Processing was all 12 sheets on reels in a Jobo tank, Xtol 1:3 @ 16.5 minutes with continous agaitation. I should have developed them for only 14.5 minutes as they are slightly over developed.

Please be patient this is my first post and I am a total graflex/rangefinder newbie...

The other day I discovered my rangefinder was completely out of calibration.
After long hours of head scratching not understanding what could ever have happened, I started thinking out loudly (making sure everybody in the house heard) of how I would question old eastern-bloc style any person who had entered the house in the last five days.
At that point a remorseful (pitiful?) one stood up for her crime and confessed that she knocked down the camera.

I tried to recalibrate by the above method using the original cam but only lasts for a while... especially if I put back the bracket cover or if I open and close the front lid.

The service manual suggests to send back the rangefinder for a rifurbished one at a nominal fee... not very helpful knowdays.

Is the "dummy" cam step necessary?
Should I remove the rangefinder assembly and double check everything?

Thanks

Daniel

P.s. sorry for the useless paragraph on how it happened but I had to share it with folks who can understand my frustration.

The moveable mirror is most likely at fault either it came loose from the frame requiring reglueing or one of the springs that hold the mirror shaft in place came off.
(I haven't been active here for a while and will most likely disappear permently in the near future.)_________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

The moveable mirror is most likely at fault either it came loose from the frame requiring reglueing or one of the springs that hold the mirror shaft in place came off.
(I haven't been active here for a while and will most likely disappear permently in the near future.)